Archive for May, 2013

This morning, during a most enjoyable walk round failing to see birds, we did see a spider with an apparent blue abdomen. It wasn’t that but a wolf spider carrying an attached egg sack. The females lay their eggs quite quickly after mating, then spin a silk bag for the eggs. They stay attached to her body until they hatch and even then for another week. Eventually the spiderlings just hang on as the sack can’t contain them any more.

I’ve taken a bit of a chance with the species name, so if anyone knows what it is without simply comparing photos and hoping that someone else has got it correct, please feel free to leap in with the right identification, but I think it looks like Pardosa amemtata. (There are quite a few species of wolf spider around).

There it was, on the old rotten trunk, and one cluster of growth was a bit more exposed, just a bit wetter than the others. It was reverting to plasmodium feeding stage. This is the first time I have seen the bright red plasmodium. It looks a bit of a mess here, but this is the amoeba like body that moves through the wood in search of food. It moves to the surface when the conditions are right, and there changes form to become the vivid orangey-pink round aethalia, which produce the spores. All my notes are here.

Along Elm walk the more mature elm suckers are in trouble. The original elms died a while ago due to Dutch Elm Disease, but their roots are still alive and are throwing up suckers at a small distance from the original tree. This year the suckers have dead branches and one is trying to throw out new branches from its trunk. Not good.

The elms in Abney are the home of the White Letter Hairstreak Butterfly colony. This butterfly is in serious decline and is on the UK Biodiversity Action Plan list of protected species and habitat. Fortunately there are other elms in Abney that have escaped the disease.

Just occasionally I feel a bit sad to find a new species of fungus… and this is one of those. The Cherry Plum with its distinctive purple foliage near the Church Street entrance is now infected with Taphrina pruni. It has got at the vast majority of the developing fruits and they are now sterile, enlarged and powdery. The fruits would usually feed many birds and insects etc so this is a loss for further into the year. It is worth a look for the oddness of these strange heavy galled fruits hanging on the ends of the lower branches. Notes are here.

The pocket plums were not discovered by me, but on a walk about foraging given by Nick from Hodmedods, a company selling British peas and beans that have grown in Britain since the ice age. It was a most enjoyable walk.

Kretzschmaria deusta, Brittle Cinder, grows on rotten stumps and logs. and is also a plant pathogen. It kills trees and lives on in the wood. It breaks down lignin and cellulose, the structural strengthening materials in broad-leaved tree wood.

Abney at the moment has a series on log piles augmented by imported wood brought in by tree surgeons. Kretzschmaria deusta fruiting bodies are covering these log piles. This particular log is interesting. The black lines running through the sawn section are zone lines, tree defences. The area around the fungal infection is cut off from the rest of the tree by a waterproof layer that includes melanin, so appears black. If too much of the trunk is blocked the tree can’t transfer water up the tree or the sugars etc from the photosynthesising leaves back down to the roots, and the tree dies. In cross-section these waterproof layers can be seen as black lines.

In this photo the zone lines are around a section of the cut log. Inside the area the wood is wetter and more degraded than outside. The Kretzschmaria deusta fruiting bodies, the flat grey growths with a white edge, have developed on the surface. This is probably the fungus that caused the tree to end up in Abney as logs. It is not often that the logs give away the secret of which fungus has invaded them.

Wood plays a huge part in the fungi in Abney, and the inkcaps are specialists in dead wood, so it is not surprising that inkcaps are among the first caps to grow fresh this year.

These were the frist new caps I saw. Glistening ink cap, Coprinellus micaceus), the most widespread of the inkcaps, orangey brown with light crystalline specks on the top.

Then there is the Coprinellus truncorum, only 114 British Records held at Kew and only on one rotting fallen tree in Abney. It looks like C. micaceus with the micaceus specks washed off the top (which can happen easily in light rain).

It takes a microscope to tell them apart.

The smallest of the inkcaps was just beginning yesterday. It grows on wood and buried wood so looks like it is growing in the ground. Coprinellus disseminatus, now officially ‘Fairy Inkcap’, but I prefer the old common name of ‘Trooping Crumble Cap’ of Fairies Bonnets’.

On woodchip piles there are 2 inkcaps. One, Coprinopsis lagopus, is traditional inkcap; transparent grey lined cap that self digests to spread its spores, eventually leaving only the white stalks. It appears as scale covered bullet-shaped, poking through the wood chips.

The last of the inkcaps is not the usual presentation. Coprinopsis marcescibilis. I always have trouble with this one. It doesn’t self-digest. It is hygrophanous, ie it changes colour depending on how wet it is, in dry weather it is opaque cream, in wet weather is grey/brown. It used to be Psathyrella marcescibilis, so it depends on how old a field guide is as to where it appears, and it does look more like a Psathyrella, with light edge to the gills.

The other 2 species I found yesterday are not inkcaps. Pluteus salicinus is a grey cap with radial fibrils on the cap surface and a slight shine as if it has been polished. There is no ring on the stem and the gills begin white and change to pale pink, (carrying a mirror to look under caps works well here).

The other cap is an untidy growth of Polyporus durus, Bay Polypore. The leathery looking surface has a white stem here as it is so new, but it does develop a black base. The underside is also white and with pores instead of gills.

A wonderful warm day today and the butterflies were flying. Brimstones ranging from lime green to bright yellow to pale, almost white, were fluttering about, on the move constantly and too high to really get close to. The orange-tips were also active, the males with the orange tips chasing the females who have dark tips but still the characteristic brownish mottling on the underside of the back wing. I saw several females laying eggs on garlic mustard, Alliaria petioilata, at the back of the bank of growth lining the main path from the front entrance to the chapel.

The white cow parsley is beginning to mass some of the paths. The dappled shade is surely something to treasure. Abney is almost at its best. Another week maybe? (May photos are here).